As a substrate processing apparatus, there has been known a semiconductor polishing apparatus that flattens a surface of a semiconductor wafer. In addition, there has been known a backside polishing apparatus that polishes the backside of a semiconductor wafer (see, e.g., Japanese Patent Laid-Open Publication No. 2014-150178). In the above-mentioned substrate processing apparatuses, a temporary placing table (substrate holding module) that temporarily holds a substrate may be used in the middle of a substrate polishing processing and a cleaning processing after the polishing. In addition, when a substrate is transferred among a plurality of substrate transfer robots, the substrate may be temporarily placed on the temporary placing table and transferred between different robots.